Rescuers look over the site where a car bomb attack happened in Kirkuk, a northern city of Iraq, April 15, 2013. (Xinhua/Dena Assad)

A spate of bomb attacks, including 23 car bombings, struck Iraqi cities, killing at least 20 people and wounding 195 in the latest escalation of violence, just five days ahead of the country's provincial polls.

The deadliest attacks occurred in the Iraqi capital of Baghdad when seven car bombs separately ripped through the city during the morning rush hour, killing 10 people and wounding some 52 others, an Interior Ministry told Xinhua on condition of anonymity.

In Kirkuk, some 250 km north of Baghdad, four car bombs separately went off in the city, killing two people and wounding 24 others, a local police source anonymously told Xinhua.

Elsewhere, three car bombs separately detonated in the city of Tuz-Khurmato some 200 km north of Baghdad, killing a total of five people and wounding some 49, a local police source said.

In the mean time, two car bombs went off in Iraq's southern city of Nassriyah, some 375 km south of Baghdad, wounding at least 14 people, the local police said.

Two more car bombs struck two towns in Babil province in south of Baghdad, wounding a total of 19 people, the police added.

In Salahudin province, two car bombs parked near an office of a political coalition running in the upcoming provincial polls detonated in the provincial capital city of Tikrit, some 170 km north of Baghdad, wounding seven people, a local police source said.

Separately, a suicide bomber blew up his explosive vest at a police checkpoint near the city of Dowr, some 20 km south of Tikrit, wounding 13 policemen, the source said.

In Iraq's eastern province of Diyala, a police officer was killed by a sticky bomb attached to his car in the town of Buhriz, near the provincial capital city of Baquba, some 65 km northeast of Baghdad, a provincial police source told Xinhua.

Separately, a car bomb went off in the city of Maqdadiyah, some 100 km northeast of Baghdad, wounding three people, while 10 more people were wounded in separate bomb and gunfire attacks across the province, the source said.

In addition, a car bomb detonated while Iraqi security forces were trying to defuse it in Tal Ubtta area, some 40 km west of Iraq's northern city of Mosul, killing a policeman and wounding two others, a local police source said.

Another car bomb went off in southeastern Mosul, some 400 km north of Baghdad, without causing casualty, while gunmen shot dead a man and a roadside bomb wounded a policeman and a civilian in separate incidents in the city, the source added.

The attacks came as the Iraqis cities were preparing for the provincial polls slated for Saturday to elect their council members.